What Is Telnet? How Do I Run It? (2024)

Telnet uses the Telnet protocol (part of the TCP/IP protocol suite) to connect to a remote computer over a network. You can execute telnet from the Command prompt.

Telnet can also test whether a port is open. This can be useful when you're having trouble connecting via IMAP/POP or when you have an SMTP appliance that won't connect. It allows you to test connectivity to a remote host on a given port, which can help diagnose the issue.

Syntax:

telnet [RemoteServer] [Port]

[RemoteServer]: specify the name of the server to which you want to connect. When you are connecting to an email server you need to use the MX record value.

[Port]: enter the port that you want to use.

How Do I Enable Telnet?

• For Windows users
• For Mac users

For Windows users:

1. By default, Windows does not have the Telnet client enabled. To install Telnet, click the Windows Start button, type in Control panel and click the Control Panel App.

   

2. In the Control Panel, click Uninstall a Program under the Programs section.

   

3. Then click Turn Windows features on or off and after you click Continue on the security prompt, you should see a list of components.

   

4. Scroll down to Telnet Client and check the box next to it. Click Ok to install the client.

   

5. To run telnet, open the command prompt. Refer to the Knowledge Base article What Is A Command Prompt? for instructions on how to do it.
6. Type in telnet [RemoteServer] [Port]. If you are trying to connect to Intermedia mail server, type in your MX record, for the [RemoteServer]. Usually, port 25 is used for this type of connection.
   Note:If it's successful, you'll see a blank screen, and if it fails, you'll receive an error message.

   

   To terminate the Telnet session use the quit command.

For Mac users:

1. By default, Mac OS does not have the Telnet client enabled. To install Telnet, open the Terminal. Read the Knowledge Base article What Is A Command Prompt? How Do I Use It On Mac? for instructions.
2. Install Homebrew on Mac OS using the Terminal command:

   /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

   

   Put in your Mac admin password to authorize the installation.

3. Use Homebrew to install telnet:

   brew install telnet

   

4. To run telnet, in Terminal, type: telnet [hostname] [port].